Rotary underreamer



July 12, 1932. TRlPLETT 1,866,736

ROTARY UNDERREAMER Filed May 10, 1926 2 Sheets-Sheet l vl E v7'0/e Man-186 3 77.961822 A1- TOENE r y 12, 1932- J. B. TRIPLETT ROTARYUNDERREAMER 2 Sheets-Sheet 2 Filed May 10, 1926 Patented July 12, 1932UNITED STATES PATENT OFFICE" JAMES B. TRIPLETT, OFIVHIT'EIER,CALIFORNIA; WILLIAM H. CAMPBELL, OF LOS ANGELES, CALIFORNIA, AND WILLIAMH. MAXWELL, OF BEVERLY HILLS, CALI- FORNIA, EXECUTORS OF SAID JAMES B.TRIPLETT, DECEASED, ASSIGNORS T JOHN GRANT, OF LOS ANGELES, CALIFORNIAROTARY UNDERREAMER Application filed May 10,

lvly present invention, like that described and claimed in my copendingapplication,

Serial No. 632,295, filed April 16th, 1923, is-

suing on March 17, 1931 as Patent No. 1,7 96,546 (upon which thisinvention may be regarded as an improvement) relates to rotary welldrilling equipment; and it relates particularly to expandingunderreamers adapted to be interposed, at an intermediate level or atthe lower endof a drill string, above an ordinary fish tail bit, or abit of any preferred design, one type of terminal bit having importantfeatures of novelty being hereinafter described.

As was observed in my mentioned former application, considerabledifiiculty is en countered, in the drilling of oil wells or the like, inmaintaining the full diameter of the bore,there being a tendency for thecorners and sides of drill bits to wear oil, so

that the resultant hole is not cut to the full intended diameter. Itbeing necessary that the diameter of the hole be maintained, in orderthat the well casing may descend freely into the well, it is oftennecessary, un-

der the indicated conditions, to employ an underreamer to enlarge thehole to full diameter; and underreamers employed for this purpose havecommonly been of an expanding type, such that they may be loweredthrough the casing to the point at which they are required to operate;but, in order to employ an underreamer of the mentioned older type, ithas commonly been necessary to pull the drill and to attach suchunderreamer to the lower end of the drill tubing, and then to lower theunderreamer into the well. In using that old construction, beforedrilling can subsequently be resumed, the underreamer must be in turnremoved from the well and replaced by the terminal bit; and it canreadily be seen that much time is consumed in the changing of tools; andthat, in drilling through hard rock, where the drill wears quickly, alarge part of the time is spent in the removing and the replacing oftools.

It is an object of this invention to provide an improved underreamerwhich is adapted to be interposed in the indicated 50 manner and usedconjointly with a terminal 1926. Serial No. 107,999.

bit, and which may be operated, with high efliciency, without removingthe bit fromthe well and either at the bottom of the well or at'anintermediate level.

It is an object of this invention to provide an end-cutting and reamingorganization of the general character referred to with parts which aremore massive and rugged and durable than those disclosed in my mentionedprior application; and, in preferred embodiments of my invention, I maydispose, within slots within a two-piece hollow body, a plurality ofseparately rotatable reaming cutters, V the use of three of thesecutters being highly advantageous as tendingto a self-centering 65efl'ect and to a uniformity of wear. I It is a further object of thisinvention to provide an organization, of the general characterdescribed, including reaming cutters which are uniform in cross sectionand which may be either replaced, in case of breakage or undue wear, ormerely turned end for end, relatively to'bearing elements, to eifect anequalization of wear.

It is anobject of my invention to provide an organization of the generalcharacter referred to comprisinga hollow main body having asplinedconnection, or the like, with a comparatively massive head whichis disposed interiorly there0f,either said body or said head beingprovided with atpin and the other of these last-mentioned elements beingprovided with a box,said pin and said box being each provided with alongitudinal passage for a circulating fluid; and, inpreferred'embodiments of my invention, I may provide means fordelivering said circulating fluid either to a terminal bit, disposedbelow my reaming organization, or to the mentioned rotatable reamingbits, the latter being pivotally movable within longitudinal slots insaid hollow body,or to both or all of said bits. i

It is a further object of my present invention to provide a reamingorganization with improved means for the support and positioning ofrotatable reaming cutters,each cutter being preferably freelyrevolublenpon a shaft, and said shaft being provided with novelsupporting means at the respective ends thereof; and, inpreferredembodiments of 100;

my invention, a support in the form of a pivoted block suitable for useat the lower end of each of the mentioned cutter-carrying shafts may beprovided with means for preventing relative rotation of said shaft andwith means for so pivoting the same as to permit the top thereof tooccupy an inner or retracted position during the lowering of my reamingorganization into a well. I It is a further object of my invention toprovide, for use in connection with a pivoted block of the generalcharacter referred to, a slidable block having a splined or dovetailedconnection with a wedge member integrallyor otherwise rigidly connectedwith the menioned interior head,-this slidable block being'provided withmeans for limiting its outward movement and with means permittingrelative rotation of the mentioned shaft, or of a member thereon,regardless of variations in the inclination of said shaft. i It is afurther object of my invention to provide means whereby the encounteringof resistance during the lowering of my reaming organization into awell, or as a result of rotating the same in a well, is efiective tocause an expansion of reaming cutters.

Other objects of my invention may be best appreciated from the followingdescription of an advantageous embodiment thereof, taken in connectionwith the appended claims and the accompanying drawings, lIIWlllCll Fig.1 is a diagrammatic general View, showing an embodiment of my inventionas employed in the enlargement of a well hole at a level below the endof a casing therein, but above the bottom ofsaid well hole.

Fig. 2 is, for the most part, a central section through a reamingorganization illustrating my invention, with parts broken away, areaming cutter being shown as occupying a retracted position, as duringthe lowering of the same into a well.

' Fig. '8 is a view corresponding to Fig. 2,

but showing a reaming cutter as occupying an expanded position.

. Fig. 4 is a'horizontal section, taken substantially as indicated bythe line el4l of Fig. 2.

Figs. 5 and 6 are respectively similar sections, taken at the respectivelevels indicated by the lines 5- 5 and 66 of Fig. 2.

Fig. 7 is a'section, comparable with Fig. 6, but taken, as indicated bythe line 7-7 of 3 at the time when reaming cutters occupy an expandedposition.

Fig. 8 is a detail perspective view of an upper or slidahle bearingblock for a rotatable reaming cutter, as hereinafter described.

Fig.9 is an elevational view of one advantageous type of terminal cutteror bit, suitable for use with an organization suchas is shown inpreceding figures, this terminal cutter or bit being of a fish-tailtype, and provided with what I may term impeller blades,

-for a lifting or resistance effect hereinafter described.

Fig. 10 is a vertical sectional view, taken substantially as indicatedby the line 10-10 of Fig. 9.

Referring to the details of that specific embodiment of my inventionchosen for purposes of illustration, I show a comparatively massivetwo-part hollow body 11 as comprising a lower section 11a and an uppersection 11?) (the latter having a threaded connection with the former at12) these sections cooperating in the provision of a chamber 13 in whichan interior member comprising a head 14 and a shaft 15, preferablyintegral therewith, is vertically movable, although incapable ofrelative rotation. To prevent such relative rotation, the head 14: andone section (as the lower section 11a of the mentioned hollow body) mayadvantageously be splined together in the general manner indicated inFig. 5; and, assuming a lubricating liquid to be downwardly delivered,as through central passages 16 and 17, provided respectively in theshaft 15, or its equivalent, and in a terminal bit-carrying extension18, at the lower end of the section 11a, or its equivalent, suchcirculating fluid may advantageously be excluded or substantiallyexcluded from the chamber 13, or from an upper part thereof by theprovision of an annular packing, as at 19, below a collar 20,-shown ashaving, at 21, a threaded engagement with the shaft 15,. On the lowerend of the head 14, or its equivalent, and preferably integraltherewith, I may provide a downwardly-diminishing wedge member 22,suitable for use in imparting lateral movement to slidable bearingblocks 23,-threeof these blocks being shown (see FigspS and 7) as havingat 21, a splined or dovetailed connection therewith, to cause, during alowering of the head 14 relatively to the hollow body 11, an expansionof any rotary or other cutters (as the substantially cylindrical reamingcutters from a position such as that in which the same are shown in Fig.2 to a position suchas that in which they are shown in Fig. 3.

As indicated, I consider it advantageous to 7 give to these reamingcutters a substantially 1 cylindrical form, roughening the surfacethereof and forming the same of a comparatlvely hard and wear-resistingmaterial;

and in order to permit of not only a rotative but a pivotal movement ofthese reaming cutters (three being an advantageous number as tending toa self-centering effect) I may employ, in conjunction with the upperslidable bearing block 23, or its equivalent, 'a pivoted lower bearingblock 26; and, assuming the cutters 25, 'or equivalent cutters, to betubularin form, I may permit the same freely'to rotate upon separateshafts 27 optionally holding these shafts agains'trotation by meanssuch'as a pin or pins 28. Using this or a similar construction, theblocks 26 being shown as pivoted upon pins 29, the cutters 25 may rotateupon the shafts 27 without imparting movement thereto, and the upperends of these shafts, whether the same are integral with hearingelements 30, or are rotatable therein or are pivoted thereto, as bymeans of pins 31, may be laterally movable by engagement within amplebearing apertures 32, in the lower surfaces of the slidable blocks 23,or in equivalent laterally movable members, the blocks 23 being shown asprovided not only with dovetailed slots 24 but with upwardly extendingheels or lugs 33; and these lugs 33, or their equivalent, may serve notonly to limit the outward movement of said sliable blocks, as byengagement with the interior surface 34 of the lower section 11a of thehollow body in which the mentioned reamers are secured, but also toclose, when said reaming cutter occupy the retracted position in whichthey are shown in Fig 2, inclined passages 35, through which, when saidreamers occupy an expanding position such as that in which they areillustrated in Fig. 3, a circulating fluid may be delivered thereto.

The downwardly-diminishing member 22- is shown as provided, at its lowerend with a coaxial short pipe 36 (glands being preferably provided at 37and 37') projecting into the mentioned chamber 17, communicating withthe interior of a terminal bit 38 of any preferred character. The shaft15, guided by the upper portion of the hollow body section 11?),carrying the gland 37, is shown as provided with a pin P; and theextension 18 is shown as provided with a box B, in order that thedescribed reaming organization may be easily interposed, at anintermediate level or at the lower end of a rotary drill string, aboveany suitable rotary bit. In order that the rotation of the describedorganization, and the consequent rotation of said bit, may be effective,when such action is desired, to produce a relative upward thrust of thementioned hollow body comprising sections 11a and 116, this bit may beof the general character separately illustrated in Figs. 9 and 10 thatis to say, assuming it to be a bit of fish tail type, it may be providedwith a diagonal impeller blade or blades 39, 39, so disposed upon itsrespective faces as to give the entire bit (which may be provided withone or more outlet openings 40, 40, for a circulating fluid) an up wardthrust whenever the described organization is rotated, in a well hole,and even though said bit shall contact only with a fluid, not being atthe bottom of the well hole; and it will be obvious that the use ofcylindrical cutters on a conical surface cut thereby, involves arelative slippage or grinding efiect which is highly efficient in itscutting action.

Although I have herein described a single complete embodiment of myinvention, it should be understood not only that various featuresthereof might be independently employed, but also that numerousadditional modifications might be devised, by those skilled in the artto which this case relates, without the slightest departure from thespirit and scope of my invention, as the same is indicated above and inthe following claims. 1 j

This application is similar in subjectmatter to my prior applicationSeLNo 632,- 295, filed April 16, 1923, the present applicationcontaining certain improvements upon the structure of the former.'Allcommon subject-matter is claimed in said prior application,'theclaims of this application being directed to said improvements.

I claim as-my invention:

l. A well reaming tool comprising: a s10 ted hollow body provided, atone end, with a guide for ashaft;'an d provided, at its other end, withmeansfor the attachment of a bit; reaming cutters pivotally movable inthe slots ofsaid hollow body, between retractedpositions and outwardlyinclined positions; blocks holding the outer parts of the reamer cuttersso that they are movable; and means, comprising an interior head havinga splined connection with said body and slidable connection with saidblocks, for laterally shifting said blocks. I

2. In an underreamer, a hollowibody having a longitudinal opening, aroller cutter for operation in the opening,a mounting for the cutterincluding a supporting member rotatably carrying the cutter having itslower end pivotally supported and a block movable rel ative to saidmember and carrying the upper end of said member, and means for movingthe block outwardly, the mounting including a part engaging the body tolimit outward movement.

3. In an underreamer, a hollow body having a longitudinal opening, aroller cutter for operation in the opening, a mounting for the cutterincluding a supporting member rotatably carrying the cutter having itslower end pivotally supported and a slidably supported block carryingthe upper end of said member, and means for moving the block outwardly,the mounting including a projection cooperating with the body to limitoutward movement.

4:- In a well reamer of the general character described, a main bodyprovided with longitudinal slots, reaming cutters pivotally secured attheir respective lower ends within said slots, and slidable bearingblocks carrying the outer end parts of said cutters and provided alsowith means limiting the outward movement thereof, said .slidable blocksbeing movable by a wedge member which is circulating fluid therethrough,said slidable blocks being so movable relatively to said passages as toclose the same when said blocks occupy a retracted position.

5. A well reamer of the character described including, a body havinglongitudinal slots, reaming cutters pivotally held at their lower endsto operate in the slots, blocks carrying the outer end parts of thecutters, and a wedge member cooperating with the blocks to move them andhaving fluid passages therein, the blocks being related to the passagesto close them when the reamer is unactuated.

6. In a rotary underreamer, two relatively longitudinally movable bodyparts rotatively locked together, expansible cutters mounted on the bodyparts and adapted to be expansively moved by relative longitudinalmovement ofsa-id parts, oneof said parts adapted for connection to arotary drill stem, a rotary drilling bit rigidly attached to the otherbody part,and said bit having vanes thereon adapted by rotative reactionwith a liquid to move the bit and the connected body partlongitudinally.

7 In combination with a rotary drilling tool having a longitudinallymovable rotatable actuating part, a drill bit rigidly attached to saidpart and having thereon a diagonal vane adapted by rotary reaction withliquid to move the bit and connected part longitudinally.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 27th day of April, 1926.

JAMES B. TRIPLETT.

